Touch-sensitive devices may detect inputs via several different mechanisms, including but not limited to optical, resistive, and capacitive mechanisms. For example, an optical touch-sensitive device may detect an input by capturing an image of a backside of a touch screen via an image sensor such as a camera, and then processing the image to detect objects located on the screen. Such a device may include an illuminant within the device to illuminate the backside of the display screen such that objects on the screen reflect the incident light toward the image sensor, thereby allowing the object to be detected.
Some optical touch-sensitive devices may acquire image data at relatively high frame rates. This may facilitate the tracking of fast motion, but also may give rise to difficulties in processing the image data with sufficient speed to avoid glitches in the tracking of touch inputs where multiple clients are accessing the image data.